angle d'incidence

OBS: L'angle d'incidence détermine l'apparence de la cible sur une image. À chaque pixel d'une image correspond un angle d'incidence local qui varie en fonction des cibles au sol : arbres, rochers, édifices etc., d'où des variations de l'intensité du pixel.
OBS: angle d'incidence : terme uniformisé par le Groupe de travail de la terminologie de RADARSAT-2 (GTTR).

CONT: The incidence angle is commonly used to describe the angular relationship between the radar beam and the ground, surface layer or a target. A change of the radar illumination angle often affects the radar backscattering behaviour of a surface or target. The incidence angle changes across the radar image swath; it increases from near range to far range. In the case of satellite radar imagery, the change of incidence angle for flat terrain across the imaging swath tends to be rather small, usually on the order of several degrees. In the case of an inclined surface (slope), the local incidence angle is defined as the angle between the incident radar beam and a line that is normal to that surface. The local incidence angle determining, in part, the brightness, or image tone, for each picture element (pixel) and slope facet, is a key element in the prominent rendition of terrain features in radar imagery.
OBS: incidence angle: term officially approved by the RADARSAT-2 Terminology Approval Group (RTAG).

CONT: El ángulo de incidencia describe la relación entre la iluminación del radar y la superficie de tierra. Específicamente, es el ángulo entre el rayo del radar y un objeto en la superficie. El ángulo de incidencia ayuda a determinar el aspecto de un objeto en la imagen.